1. Field of the Invention
The present invention relates to load handling systems, and in particular to an apparatus for separating flat unit loads such as letters, newspapers, periodicals and the like and for delivering them to a conveying system.
2. Description of the Prior Art
Machine-readable postal zip-codes are indicated on mailings such as letters, postcards, packages and the like as an identifier for a location, a delivery area, a Post Office Box or a bulk recipient enabling fast distribution of the mail by machine. The sorting of the incoming mailings ensues, for example, with the assistance of controllable flat unit load carriers that are respectively loaded with a mail shipment in specific loading locations. The mail shipment is then delivered to a sorting container or a corresponding sorting compartment allocated to the respective postal zip-code. Since the sorting containers or sorting compartments can be arranged in various levels, the flat unit load carriers circulating at conveyor devices must also be potentially able to bridge different height levels.
After the transfer of the mail shipment to the allocated sorting container or the allocated sorting compartment, the empty flat unit load carriers can be reloaded with another mail shipment when passing a loading location. For example, the loading of the flat unit load carriers ensues with the assistance of a circulating impeller wheel whose blades form cells that accept the flat unit loads that are already separated and incoming on a conveyor means and deliver them to the circulating flat unit load carriers. The separation and the transfer of the flat unit loads to the conveyor means leading to the impeller wheel must thereby be undertaken with a relatively high precision matched to the processing speed of the overall sorting means.
Comparable sorting jobs also derive in what is referred to as the remission of periodicals, newspapers or other such publications. The publications not sold by individual dealers are returned to the wholesaler where the publications are sorted out for disposal or are sorted anew for being returned to the respective publisher.
The automatic handling and, in particular, the separation of unpackaged periodicals or newspapers presents considerable difficulties both in the distribution of postal matter as well as in the remission of the publications. When handling the publications with automatic gripping devices, several problems may arise. The publications may open, causing damage or destruction of the publication. These problems may further lead to an interruption of the overall sorting process.
German OS 1 917 795 discloses a conveyor means for page-shaped objects, which means operate with suction air. A stack of objects is moved in a horizontal direction with vertically oriented objects and is brought to a transport drum provided with suction air openings. A removal drum is located above the transport drum. The transport drum pulls the objects from the stack directly upward to the removal drum.
Further, Swiss Patent Publication No. 664748 discloses a device for separating sheets that are brought from a stack to a transport drum from above and that are transported directly to a laterally arranged deflection means by the transport drum.